Exploring exosome data to identify prognostic gene signatures for lung adenocarcinoma

Background: Exosomes are involved in tumorigenesis, growth and metastasis. However, the prognostic value of exosome-related genes in lung adenocarcinoma (LUAD) remains unclear. Methods: Clinical and transcriptome data from The Cancer Genome Atlas LUAD cohort were used to construct a model based on exosome-related genes, which was validated with LUAD data from the Gene Expression Omnibus (GEO). Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis were used to explore underlying mechanisms; the single-sample gene set enrichment analysis score was used to determine immune functions. Results: A 19-exosome-related gene signature for overall survival in LUAD was predictive in both The Cancer Genome Atlas and GEO LUAD cohorts. Immune-related and extracellular matrix-related pathways were enriched in differentially expressed genes. Immune states differed between high- and low-risk groups. Conclusion: The novel signature can be used to predict outcomes in LUAD.Lay abstract Exosome products are related to tumorigenesis, growth and metastasis, and also have potential prognostic value in lung cancer. The data and information for lung adenocarcinoma patients retrieved from databases were used to develop a risk score model. The molecular mechanisms and immune system activity in high- and low-risk groups of patients with lung adenocarcinoma based on the median risk score were obviously different. The risk score model contained 19 related genes. Patients with low-risk scores had better prognoses. The novel risk score model can be used to predict the outcome for patients with lung adenocarcinoma.